Comment 20 for bug 1516451

The reason why this alert pops out is related to running sosreport on this node. Nagios can not access it - which is good as this directory is only accessible by root:
# ll /sys/kernel/debug/ | grep trac
drwx------ 8 root root 0 Jul 9 09:06 tracing/

To validate/replicate this behaviour, please open three terminals.

Terminal 1, run
mount | grep -i tracing
- no output here as this directory is generally not presented by mount

Terminal 2:
mkdir testing; cd testing
while true;do mount | grep -i tracing > mounted-$(date +%s); done

on terminal 1 please run
cd testing
watch ls -lt

Terminal 3
sudo sosreport -a --all-logs

Watch Terminal 1. On the beginning, you will see files created with 0 in size. When you start sosreport in another window/tmux this file gets populated - meaning munt can see it.
Why does it become available? Sosreport gathers diagnostic information and initiates it. This directory is not visible from mount during normal operation.